Studies involving the movement of drugs into saliva are being conducted using intact animals (rat, dog, cat, ferret), perfused glands (rat, cat, dog) and slices of submaxillary and parotid glands (rat, dog, cat, ferret). The mechanisms of movement of salicylate, nicotine, penicillin and diphenylhydantoin (DPH) have been reported. Further studies with DPH are planned to identify effective inhibitors of active transport. The following studies are in progress: 1) the influence of age on drug movement across the salivary membrane; 2) characterization of the biotransforming properties of salivary tissue (inducable or not); 3) correlation of blood and saliva levels of THC with observed behavioral effects; 4) the mechanism(s) of action of THC on salivation; 5) the effect of histamine, epinephrine and acetylcholine on drug movement.